Robindonne

11 minutes ago, BlueStinger said:

Magic Lantern is compatible with the 6D and as far as I know it will allow for more than 30sec exposures.

Oh thx for the quick reply.  Although im planning for a 60d instead of 6d.  Maybe the 6d is in the end a better choice. I do want to have not much weight in the camera.  And therefore skipped the search for a5d.  They go cheap although so maybe retake some looks on this 5d and the 6d.   Was just watching at features of magic lantarn builds but couldn’t find the intervalometer yet.  Took a 3” exposure on the site so have to dive in a bit deeper.  While looking at the features of magic lantarn i did notice the lack of knowledge i suffer with dslr camera.  Am i diving in a hard to learn menu style or are these extras just extras added to the standard options.  And fully controllable through menu on the camera or are laptops needed?

Lol thanks for all the links.  I do think I mistyped my question.  Of course very thankful for the links. They might be very helpful when canon or magic lantarn doesnt do it without an external piece of equipment.  But my main goal was to try to skip this piece.  I kind of made a choice about the canon model, a 60d. Cheap, dust and waterproof, that nice flip-lcd screen and the last thing that came up was the intervalometer.  And that is the part im not sure the 60d is the almost perfect choice for me.  Im Sure it doesn’t have it standard in the options so might check today if magic lantarn can be used at this model. Not sure if an internal intervalometer lets you choose for longer then 30 sec anyway.  And if no and no then the external intervelometer advices are very helpfull.   Thx for all advices 

Ha okay.  Maybe i will one day open a topic about the pros and cons of small sct over apos.  But it was definitely you who commented.  I remember the guy standing next to a colossal white dobson😅.  But ok.  Somehow i know big refractors must have something extra over. Sct.  Why would one buy an expensive piece of equipment when better results can be achieved with a much cheaper and lighter small sct.   Cant tell the answer for now but maybe i ask one day.  Im sure someone will explain in full color.  Thx.  

10 hours ago, John said:

Bear in mind that you probably won't get 2.5x doing it that way. Probably more like 1.5x but the exact amplification will depend on the focal length of the barlow lens and the distance between the eyepiece lenses and the barlow lenses.

 

Oh and John, a little off topic but okay, i once advertised an c5+ on this forum.  For sale or to swap.  And remember you telling me to not need an apo because the c5+ is some sort of, or is, an apo.  The scope is still for sale and biddings came from 50,- to 600,-   I received like 10/15 mails asking me to sell for 600,-  people who were not on a hunt for a scope but were willing to add that white celestron to their arsenal.  Maybe its not worth more then that. I dont know.  And still dont use the c5.  But you told me the set was fine, the accessoires were plenty to start with etc etc.  And when reading all these messages from ex-owners who were sorry they sold this scope in the past, im really thinking of keeping it for moments with family or my kids to look back in time through a scope that was also made back in time. My only (semi)apo refractors i own are a 71 and 80 mm zenithstar.  Do you still think its not worth to search for an used 100 or 120 mm apo to complete my own collection, keeping in mind that we always will carry a shoppinglist of items we terribly need😅, or do refractors have some pro’s to consider over using a sct?   Ill probably keep the c5.  But your comment made me think about the terrible need for a medium to big apo.   Thx for reading a long and boring question

9 minutes ago, Alien 13 said:

Giga T pro 2 cant do it all and still rely on some internal camera settings 

Ok.  Do you use one?  Do you suggest to search for a wireless one?  My first idea was, if canon never made a complete model, to look for wired.  Just because batteries and a free hotshoe for a rdf maybe?!  Im not really fanatic on daytime photography so probably never gonna make a family-picture from a long distance.  Actually never make family-pictures anyway😬. And phones are always present for these unique moments

28 minutes ago, The Admiral said:

Not the Canon but I have a Fuji X_T1 and that has a built in intervalometer but it only goes up to 30 second exposures. May be other cameras have longer exposures possible.

This was OK when I used to do Alt-Az imaging, but since acquiring an EQ mount I want to take longer subs. I've just got one of these. It sits in the flash mount and a short cable goes to the camera remote release socket. It is controlled by a remote handset which communicates via wi-fi with the shutter release. So if all else fails, you could go down this route. They can be bought for use with different cameras, just the interconnecting lead is changed.

Ian

Thx and probably also a good camera but some brands are not supported sadly so have to search for a compatible canon or nikon.  Or just skip the dslr fase and jump to zwo cameras.  The stupid thing is that at this moment i start to realize i shouldnt have sold a lot of stuff that was included in a second hand set i bought.  Sold the polemaster.   asi178.  A 60 mm guidescope with an altaircam.  I m not gonna tell for how much(less) i sold it because im gonna kick myself probably.  And that was just some months ago when not knowing what to do with these items🙄

Yes so a remotecontrol is probably the best option.  I will look into the different given options then.  Unfortunately.  If canon didnt make a model with these features combined then there is no other way to buy one of the remotes.  The magic lantarn sounds familiar. Ill have a look ofcourse but when its capable of programming series of long exposure times then i guess any canon will have that option? Or are some models excluded?   And due to the lack of a list with dslr’s who have this option im still curious if someone can advice me.  Thx.  Dankjewel

Glad i found a place to ask question.  I recently watched a clip from nico carver and he gave some advice about using a dslr.  Im quite new to all thats related to astronomy.  But while using a nikon dslr without the ability to be controlled by asiair, im searching for an almost perfect dslr.  The best option is probably a full frame but in the price range around € 400/500 i wont find one with a flip-screen. So cropped sensor is my only option.  But the nico carver clip mentioned an intervelometer build in a camera.  So I understand that when the dslr is attached to just a scope without my asiair im still able to shoot multiple frames without paying attention to the camera?  Im asking for advice and maybe experience in canon dslr with a rotatable screen ánd intervelometer.   I just cant find a list with possible models of the eos.  Right know im thinking of buying an used 60d.  They go for 200€ in good shape.   If someone can advice another model im very curious.  Oh and the 60d should be sealed and weatherproof so the suggested one must have that also

I like that way of thinking.  Also want to use a 71 mm apo for guiding an 8” sct.  If the mount can handle the weight and you can double use the small apo now and then, why buy a single purpose mini refractor for guiding? Most of them cost the same as a used small apo. And for backup buy a small oag adapter when using the small apo as main scope

5 hours ago, alacant said:

+1.

It's a re-badged 4-element gpu. A different beast to the 2 element ccs.

You need a m48 t-ring to attach it to your camera and you're good to go. But any of the above mentioned ccs will work fine:)

Cheers and HTH

Oh indeed.  It looks like it is indeed the same item.  Just better priced.  So correcting coma has recently become a cheap job.  Thx

Ok thx for the info.   Well if its only me questioning this than a software change is  probably not going to happen.  So when i switch to moon tracking rate, on these banal nights, i have to remember to set it back to star tracking rate.  At least when im unguided and planning to try some more photography   Thanks

Ok thx i will have a look.  Although i bought some months ago a complete set from a retired passionist.  Which also included a powermate. 1,25”.  But the gso brand and its other branded products do seem to work well.  Ill think about it. Thank  you again

I have the same questions about the right coma corrector.  When i bought my first used scope.  A quattro the owner told me to buy a coma corrector. At that time it was an item sold for 600,-??? Never bought is but recently i saw, i think the same, coma corrector priced at 250,-,. A skywatcher aplanatic f4 corrector. 
 

but im a rookie as well so dont pin me on my words😅

On 20/01/2020 at 16:57, g-rex said:

That's great advice! Thanks, I'll have a look at it 👍

That’s exactly how i tried to fix this issue.  I gave my daughter an LX75 mount and faced the same problem.  I did use a foam ring however.  To not have huge pressure on the barrel but to only have a small buffer for movements inside when the mount is moved.  Ive never checked it actually because her mount is not used at the moment.  I think it helps though 

16 minutes ago, John said:

Bear in mind that you probably won't get 2.5x doing it that way. Probably more like 1.5x but the exact amplification will depend on the focal length of the barlow lens and the distance between the eyepiece lenses and the barlow lenses.

 

Ok i will.  It looks like its an mostly unsatisfying buy😬.  The first thing i noticed was that the lens itself was more like an 1,25 inch size.  But maybe its common with 2” barlows. I dont know.  But all these efforts instead of using the powermate for example is probably gonna make the wo apo-barlow a collectors item in the way of not having any other purpose then collection

Ok another short question.  For the moment im trying photography without guiding.  The synscan menu showed me some options in trackingspeed( in our language it says followspeed). Does synscan automatically adjust this speed based on the object it slewed to?   And if so, when using skysafari instead of the synscan handcontroller, does the mount also know what the target and its trackingspeed is?   Sometimes i set it on “moonspeed” if my children for example wanting to have a look or when nothing else is worth watching at that night. Do i have to manually set it to normal trackingspeed when finished, or does the mount adjust it by itself?

Ow not that bad of an idea.  A short moment of thinking of cutting de 2” tube shorter if really unusable was immediately deleted because damaging it and not get getting any closer because of the barlow thickness itself.  Wouldnt gain a mm with that.  But directly attaching might help.  Ill try and let it know.  Thx

Ah ok.  I couldn’t remember what direction i came in short. Thx.  

To keep the question flow moving i have another rookie question.  I bought some months ago an old william optics barlow.  A 2”.  I immediately ran into a problem of not getting any focus with an old zenithstar 80. I dont have any extension tubes or something like that. But is that what i need to get focus? Because the barlow itselfs is like 12 cm long. Or should i just sell it and use smaller eyepieces?

When keeping in mind that one day you will sell it for upgrading your arsenal i would go for the skywatcher.  In my opinion it sells easier then bresser.   So a lower startprice and a higher sellprice sounds the most obvious choice.  At least when quality is almost the same.  I do know my Quattro 8 has a very poor focusser, dont know the quality of the bresser one so cant compare.  But I always compare these issues with buying my woodworking tools.  Festool is a bit more expensive but the depreciation after some years is less then unknown/unpopular brands.  

3 minutes ago, apophisOAS said:

But when you align to another star or 2 it will change the mount anyway so no point moving Polaris to the centre before that as its a good idea to align near your target.

Roger

Thx and I understand.  Just to be sure polar aligning with my mainscope would be safe and (almost) as good as with the polarscope

8 minutes ago, miguel87 said:

The level of accuracy being discussed here is insanely unnecessary.

Is the OP doing advanced astrophotography or visual observing?

No not at all actually.  Just starting this addiction. Amateur astrophotography i mean.  But always wondered why mounts dont have a home position mark.  Excepts for some meade mounts i looked at.  And was also wondering what is causing the happiness when people look at guide graphs that show minor adjustments.  Why not be happy when its straight and un-adjusted.  But a lot of these questions are answered and showed me the reasons and the need of guiding instead of just tracking

3 minutes ago, apophisOAS said:

When i am polar aligned i can see Polaris in the scope and guidescope without moving it , are you the same.

Roger

Well i meant pointing the polarscope on polaris itself( off polar-alignment) and then center polaris in the eyepiece of the mainscope to align the two.  And to determine the home position.  Ive never tried it.  tonight perhaps.  

16 minutes ago, IanL said:

A Polemaster does NOT depend on being well aligned though. The software determines the centre of rotation in the series of images, so any misalignment is automatically taken to into account. (Same for Sharpcap). That is why they are superior at alignment.

You mean asiair and sharpcap? Or polemaster and sharpcap? Ive never used the polemaster because i sold it before i new how great it is and what it does.  But how it takes multiple images i dont know. I thought it was stuck to the mount.  And didnt move at all.  I hope you meant asiair and sharpcap because asiair is what im planning to use for my polar alignment.  I now only use it to connect my mount with SkySafari.  Photographing with my incompatible dslr is not possible.  Also polaralignment is not possible for me right now.  But my very near future plans to upgrade some gear, mount and camera, are based on planning to align with asiair.  

18 minutes ago, IanL said:

You're confusing three different concepts:

1. Polar alignment refers to the alignment of the RA axis of the mount so that it is parallel to the Earth's axis of rotation. Neither the mount's home position nor the scope's cone error have any bearing on this.

- You can polar align using the mount's polar scope. This is subject to a number of cumulative sources of error; how well the polar scope and reticule are aligned to the mount's RA axis, and your ability to precisely align Polaris on the reticule over several steps to find the appropriate hour angle. Usually this can be done well enough for visual, but unlikely you'll get within more than a few arcminutes of the pole unless very experiences.

- You can't really use the main scope for this job, as it is subject to cone error, and you do not need to centre on Polaris, but position Polaris in the field of view such that the North Celestial Pole is centred (assuming no cone error).

- Much easier is to use a Polemaster or something like Sharpcap. These don't rely on any precise alignment of anything. They take an image of the sky through the camera (dedicated or through your main scope respectively). You then rotate the mount approximately 90 degrees in RA and a second image is taken. By plate solving both images, the software can determine the centre of rotation in the image, and therefore exactly where the mount's RA axis is pointing (not the camera or scope, the axis). You then adjust the mount until the axis is pointing at the correct position in the sky, very precisely determined by repeated imaging and plate solving. You can achieve a few arc seconds of accuracy very easily, the limit being the mechanical stability of the mount and the coarseness of the alt-az adjuster threads.

2. The home position is only important for mounts that don't have absolute encoders (such as many Skywatcher mounts). The mount controller (handset, EQMod, whatever) only knows where the mount is pointing by counting the number of steps the RA and Dec stepper motors have been told to move. This is unlike an absolute encoder which will usually start from a defined index position (found automatically using a sensor), with the encoders counting the rotations of a given gear axis electronically and reporting back to the controller the encoder position, which the controller converts in to RA and Dec.

The problem with stepper counter control is that you have to know where you are starting from. There is no absolute position as such, so the controller can only determine that a given axis has moved X steps (and thus degrees) clockwise or anticlockwise from wherever the mount was pointing when it was switched on. Thus the need for a home position, so that the mount can assume a given start location and go from there. If your home position is off a bit, you'll be correspondingly far off after your first slew to a target. You can of course correct this by moving the mount on to target and syncing the handset or EQMod which updates its pointing model to eliminate this error slightly.

3. Cone error also induces slews to be off target since the handset will of course assume that the scope is pointing at the Celestial Pole (not Polaris) when in the home position. Again the pointing model can and will compensate for this as you do more corrections and syncs, but it is desirable to get a good home position and tune out any cone error mechanically to make life less difficult for the visual observer. For an imager, just use plate solving once you are polar aligned; there are numerous free plate solvers and most capture software supports one or more of them, and it literally saves hours when the software finds the target unaided.

The challenge with having a set of home position marks made by the manufacturer is perhaps that you can rotate the dovetail clamp by 90 degrees to accommodate a side-by-side bar? I don't see any reason why they couldn't put fixed index marks at 90 degree intervals around both halves of the RA and Dec Axes to be honest, it would save 10 minutes with stickers and fine-tipped pens, but I suppose there would be additional work to adjust everything so they were properly aligned and represented the actual home position.

No you’re right about polaris and the celestial pole.  I mis-typed that word.  I know a good alignment means polaris is always off center, off the real celestial pole.  But based on so many factors a polarscope can be off alignment with the mount and I think also a polemaster can suffer minimal off alignment with the mount.  Due to attachment on paint etc.  Thats exactly why i believed a polaralignment can be done with the mainscope.  But encoders or no encoders, the scope should be pointed exactly to the celestialpole for this mainscope polar alignment.  Thats why i wondered why the can not mark the mount of factory.  But all made sense when cone error was mentioned.  A home position is just not possible, at least not for the reason i think i need it: asiair polaralignment.  
 

The guidescope will have to correct these small errors.   I do wonder if someone ever  accomplished a zero adjusted guiding. I mean No corrections? And how they did it